The deadly Ebola outbreak is spreading rapidly and has already claimed more than 700 lives. As the virus continues to rear its ugly head in West Africa, concerns are being raised over the availability of a cure to control the outbreak.

Recently, we reported that two American health aid workers had to be transported back to Atlanta, U.S. for treatment.

A possible means of controlling the Ebola outbreak would be through vaccines that can immunize those that are at risk. Even though the Ebola virus was identified in West Africa nearly four decades ago, no vaccine or licensed drug exists to combat the disease.

So why are there no vaccines for Ebola?

"It's not economically viable for any company to do this kind of research because they have stockholders to think about," says Ben Neuman, a virologist at the University of Reading in Britain.

Money is a constraint and most companies do not wish to invest in its research and find a viable cure as the disease is affecting only Africans according to British doctor John Ashton. Per Ashton, the minority factor plays an integral role in deterring research and development of vaccines, a similar situation to Aids for which treatments were only developed post their affect in western nations as well.

"We must also tackle the scandal of the unwillingness of the pharmaceutical industry to invest in research to produce treatments and vaccines, something they refuse to do because the numbers involved are, in their terms, so small and don't justify the investment," wrote John Ashton, President of the UK Faculty of Public Health.

However, all is not lost as some vaccines are being developed and an experimental treatment was conducted on an ailing American aid worker per the organization she works for.

The U.S. National Institute for Health too has developed an Ebola vaccine which it will test on humans for the first time in September this year. The vaccine is in phase 1 clinical trial and would potentially be ready for administration by end 2015, but its effectiveness remains questionable.

Moreover, there's a road block as even if the study is a success, it is not possible that the vaccine is administered to a large population and some individuals may be exposed to the virus at some juncture.

With no specific vaccine to treat the Ebola virus, health aid workers, doctors and nurses look to ease symptoms like vomiting and headaches associated with the ailment, as well as keeping those affected hydrated.